U.S. patent number 10,619,322 [Application Number 16/223,164] was granted by the patent office on 2020-04-14 for dry-bulk tanker, conveying system for a dry-bulk tanker, as well as work train.
This patent grant is currently assigned to Wirtgen GmbH. The grantee listed for this patent is Wirtgen GmbH. Invention is credited to Cyrus Barimani, Frederic Hess, Christoph Menzenbach.
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United States Patent |
10,619,322 |
Menzenbach , et al. |
April 14, 2020 |
**Please see images for:
( Certificate of Correction ) ** |
Dry-bulk tanker, conveying system for a dry-bulk tanker, as well as
work train
Abstract
A dry-bulk tanker for the provision of binding agents for soil
stabilization for a spreading device comprises a storage container
(10) for binding agent. A mechanical conveying device (18) for
conveying binding agents from the storage container (10) into an
intermediate chamber (20) is connected to the storage container
(10). A pneumatic conveying device (36) for conveying the binding
agent to the spreading device is connected to the intermediate
chamber (20). A pressure relief device (40, 41) is connected to the
mechanical conveying device in order to avoid the entry of
compressed air into the storage container (10). The invention
furthermore relates to a conveying system for a dry-bulk tanker and
to a work train for working soils with a self-propelled ground
working machine and a dry-bulk tanker.
Inventors: |
Menzenbach; Christoph
(Neustadt, DE), Barimani; Cyrus (Konigswinter,
DE), Hess; Frederic (Montabaur, DE) |
Applicant: |
Name |
City |
State |
Country |
Type |
Wirtgen GmbH |
Windhagen |
N/A |
DE |
|
|
Assignee: |
Wirtgen GmbH
(DE)
|
Family
ID: |
64745937 |
Appl.
No.: |
16/223,164 |
Filed: |
December 18, 2018 |
Prior Publication Data
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|
|
|
Document
Identifier |
Publication Date |
|
US 20190194896 A1 |
Jun 27, 2019 |
|
Foreign Application Priority Data
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|
|
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Dec 22, 2017 [DE] |
|
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10 2017 223 698 |
|
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
B60P
3/2245 (20130101); E01C 19/2025 (20130101); E02D
3/12 (20130101); E01C 21/00 (20130101); E01C
19/205 (20130101); E02D 3/126 (20130101); B65G
53/50 (20130101); B65D 90/00 (20130101); B60P
1/56 (20130101); E01C 2019/2065 (20130101) |
Current International
Class: |
E02D
3/12 (20060101); E01C 19/20 (20060101); B60P
3/22 (20060101); B65G 53/50 (20060101); E01C
21/00 (20060101); B60P 1/56 (20060101) |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
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2939648 |
|
Apr 1981 |
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DE |
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3910617 |
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Oct 1990 |
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DE |
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202008012104 |
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Mar 2010 |
|
DE |
|
102009008884 |
|
Aug 2010 |
|
DE |
|
102012021421 |
|
Apr 2014 |
|
DE |
|
2388217 |
|
Nov 2011 |
|
EP |
|
Other References
EPO search report for corresponding application No. 18213633.3,
dated Aug. 28, 2019, 3 pages (not prior art). cited by
applicant.
|
Primary Examiner: Oquendo; Carib A
Attorney, Agent or Firm: Beavers; Lucian Wayne Patterson
Intellectual Property Law, PC
Claims
The invention claimed is:
1. A dry-bulk tanker for the provision of binding agent for soil
stabilization to a spreading device, the dry-bulk tanker
comprising: a storage container for the binding agent; at least one
intermediate chamber; at least one mechanical conveyor configured
to convey the binding agent from the storage container to the at
least one intermediate container, the at least one mechanical
conveyor including a rotary feeder including a plurality of
conveying chambers, and the at least one mechanical conveyor
including an isolated area wherein any one of the conveying
chambers passing through the isolated area is connected neither to
the storage container nor to the at least one intermediate chamber;
a pneumatic conveyor configured to convey the binding agent from
the at least one intermediate chamber to the spreading device; and
a pressure relief device connected to the isolated area of the at
least one mechanical conveyor.
2. The dry-bulk tanker of claim 1, wherein: the at least one
mechanical conveyor comprises a gravity conveyor.
3. The dry-bulk tanker of claim 1, wherein: the pressure relief
device includes a vent line connected to the storage container.
4. The dry-bulk tanker of claim 1, further comprising: a positive
pressure outlet communicated with the storage container; and a
filter configured to prevent binding agent from passing through the
positive pressure outlet.
5. The dry-bulk tanker of claim 4, wherein: the pressure relief
device includes a line communicated with the positive pressure
outlet.
6. The dry-bulk tanker of claim 1, wherein: the pneumatic conveyor
includes a compressor and a pressure line connecting the compressor
to the at least one intermediate chamber.
7. The dry-bulk tanker of claim 1, wherein: the at least one
mechanical conveyor includes at least two mechanical conveyors
configured to convey the binding agent from the storage container
to the at least one intermediate chamber.
8. The dry-bulk tanker of claim 7, wherein: the at least one
intermediate chamber includes at least two intermediate chambers;
and each of the at least two mechanical conveyors is connected to a
separate one of the at least two intermediate chambers.
9. The dry-bulk tanker of claim 8, wherein: the at least two
intermediate chambers are arranged in series with respect to the
pneumatic conveyor.
10. The dry-bulk tanker of claim 1, wherein: the pneumatic conveyor
includes a conveying line configured to feed the binding agent from
the at least one intermediate chamber to the spreading device, and
the pneumatic conveyor includes a pneumatic bypass line bypassing
the at least one intermediate chamber and connected to the
conveying line.
11. A conveying system for a dry-bulk tanker for the provision of
binding agent for soil stabilization to a spreading device, the
conveying system comprising: at least one mechanical conveyor
configured to convey binding agent; at least one intermediate
chamber configured to receive the binding agent conveyed by the at
least one mechanical conveyor; wherein the at least one mechanical
conveyor includes a rotary feeder including a plurality of
conveying chambers; and wherein the at least one mechanical
conveyor includes an isolated area, and any one of the conveying
chambers passing through the isolated area is connected neither to
the storage container nor to the at least one intermediate chamber;
a pneumatic conveyor configured to convey the binding agent from
the at least one intermediate chamber to the spreading device; and
a pressure relief line communicated with the isolated area of the
at least one mechanical conveyor.
12. The conveying system of claim 11, wherein: the pneumatic
conveyor includes a compressor and a pressure line connecting the
compressor to the at least one intermediate chamber.
13. The conveying system of claim 11, wherein: the pressure relief
line connects the isolated area to the storage container.
14. The conveying system of claim 11, wherein: the at least one
mechanical conveyor includes at least two mechanical conveyors
configured to convey the binding agent from the storage container
to the at least one intermediate chamber; the at least one
intermediate chamber includes at least two intermediate chambers;
each of the at least two mechanical conveyors is connected to a
separate one of the at least two intermediate chambers; and the at
least two intermediate chambers are arranged in series with respect
to the pneumatic conveyor.
15. A work train for working soils, the work train comprising: a
self-propelled ground working machine including a milling or mixing
rotor arranged in a rotor housing, and including a spreading device
for spreading binding agent; and a dry-bulk tanker including: a
storage container for the binding agent; at least one intermediate
chamber; at least one mechanical conveyor configured to convey the
binding agent from the storage container to the at least one
intermediate container; a pneumatic conveyor configured to convey
the binding agent from the at least one intermediate chamber to the
spreading device; and a pressure relief device including a vent
line communicated with the at least one mechanical conveyor;
wherein the at least one mechanical conveyor includes a rotary
feeder including a plurality of conveying chambers; and wherein the
at least one mechanical conveyor includes an isolated area, and any
one of the conveying chambers passing through the isolated area is
connected neither to the storage container nor to the at least one
intermediate chamber, and the vent line is communicated with the
isolated area of the at least one mechanical conveyor.
16. The work train of claim 15, wherein: the spreading device
includes a buffer container for the binding agent; and further
comprising a conveying line connecting the pneumatic conveyor to
the buffer container.
Description
BACKGROUND OF THE INVENTION
1. Field of the Invention
The invention relates to a dry-bulk tanker for the provision of
binding agents for soil stabilization for a spreading device, as
well as to a conveying system for a dry-bulk tanker. Furthermore,
the invention relates to a work train for working soils with a
self-propelled ground working machine and a dry-bulk tanker.
2. Description of the Prior Art
An improvement or stabilization of soils can be effected in
particular by means of dry binding agent such as, for example, lime
or cement. To this end, the binding agent is introduced into the
soil in order to, in particular, increase the load-bearing capacity
of the same. Soil stabilization is performed in particular in the
construction of roads or railway lines, as well as in the
construction of industrial sites.
Binding agent spreaders are known for the purpose of spreading
binding agent. Such vehicles comprise a large container for the
reception of binding agent. The spreading of binding agent is
effected in such a fashion that the spreading vehicle drives ahead
of the stabilizer or recycler. An upper layer of a surface to be
stabilized is milled off by the stabilizer or recycler by means of,
for example, a milling/mixing drum, the milled-off material is
optionally mixed with further material, and spread again. The
binding agent spread by the binding agent spreader ahead of the
stabilizer or recycler is also picked up as part of this process.
It is of disadvantage with such binding agent spreaders driving
ahead that the binding agent may drift. This increases the costs as
a result of the increased material requirement and leads to dust
exposure for the workers and residents.
Moreover, stabilizers and recyclers are known which comprise a
binding agent spreader. Such stabilizer or recycler with integrated
binding agent spreader is known, for example, from DE 10 2009 008
884 (U.S. Pat. No. 8,511,933). It is hereby possible for the
binding agent to be spread, for example, directly ahead of the
milling/mixing rotor so that the binding agent is picked up
immediately by the milling/mixing rotor. In this process, there is
no hazard of drifting. On the other hand, such stabilizers or
recyclers with integrated binding agent container have the
disadvantage that such binding agent container has a small filling
volume and must therefore be filled regu-larly. The filling of such
binding agent container is effected by means of a dry-bulk tanker.
Binding agent is fed from the dry-bulk tanker to the binding agent
container of the stabilizer or recycler at regular intervals.
Feeding is effected, for example, pneumatically. To this end, the
binding agent container of the dry-bulk tanker is pressurized for
the filling process. Filling the container of the stabilizer or
recycler while driving is possible to a limited extent only.
A work train comprising a dry-bulk tanker and a milling vehicle is
known from DE 20 2008 012 104. The milling vehicle comprises a
storage container for dry bulk material such as a binding agent.
Said container features a small volume and is, insofar, filled
permanently by the dry-bulk tanker. In this arrangement, the
dry-bulk tanker is designed in such a fashion that it is not
necessary to pressurize the entire binding agent container of the
dry-bulk tanker. Rather, a mechanical transport device is arranged
inside the binding agent container of the dry-bulk tanker which
conveys the dry bulk material into a chamber by means of, for
example, a conveying screw. From the chamber, the dry bulk material
is thereupon conveyed to the storage container of the milling
vehicle pneumatically via a transport line. However, it is of
disadvantage in this design that, due to the pneumatic conveying
process, a swirling of the binding agent takes place also inside
the binding agent container of the dry-bulk tanker. This may lead
to an inconsistent feed of binding agent to the storage container
of the milling vehicle. Furthermore, there is the disadvantage that
an increased dust development occurs inside the dry-bulk tanker.
This leads to higher loads of the filter systems and may
furthermore also give rise to malfunctions of sensors, in
particular, of filling level sensors arranged inside the dry-bulk
tanker.
SUMMARY OF THE INVENTION
The object of the invention is to create a dry-bulk tanker for the
provision of binding agent for soil stabilization for a spreading
device with which a reliable feed of binding agent is possible, as
well as to create a corresponding work train.
The object according to the present invention is achieved by a
dry-bulk tanker, a conveying system for a dry-bulk tanker, and a
work train for working soils such as roads, railway lines,
industrial sites etc. by means of a ground working machine and a
dry-bulk tanker as disclosed herein.
The dry-bulk tanker is used, in particular, to fill a binding agent
container of a ground working machine, such as a stabilizer or
recycler, as described, for example, in DE 10 2009 008 884 (U.S.
Pat. No. 8,511,933). The dry-bulk tanker according to the present
invention for the provision of binding agent for soil stabilization
for a spreading device comprises a storage container for the
binding agent. A mechanical conveying device is connected to the
storage container. The binding agent is conveyed from the storage
container into an intermediate chamber by means of the conveying
device. A pneumatic conveying device is connected to the
intermediate chamber. The binding agent is conveyed to the
spreading device by means of the pneumatic conveying device,
wherein the spreading device comprises, in particular, a storage
container or intermediate buffer, respectively. The spreading
device is specified, in particular, directly on a ground working
machine. According to the present invention, a pressure relief
device is connected to the mechanical conveying device. An entry of
compressed air into an area of the storage container of the
dry-bulk tanker in which a swirling-up of the binding agent in the
storage container of the dry-bulk tanker would interfere with a
reliable conveying process is essentially avoided by means of the
pressure relief device.
The pressure relief device may be a valve connected to the
mechanical conveying device. Pressure possibly forming in the
mechanical conveying device may be reduced or compressed air
discharged, respectively, via the valve. The compressed air in
question may be immediately discharged into the environment,
wherein it is preferred for a filter device to be specified in
order to prevent an escape of binding agent. In particular when
specifying a filter device, it is not necessarily required to
additionally specify a valve. A corresponding discharge opening in
the mechanical conveying device through which the compressed air
can escape is sufficient.
The mechanical conveying device is, for example, a gravity
conveyor. In this design, conveying of the binding agent may be
effected, in particular, based on the own weight, wherein conveying
of the binding agent may also be assisted, for example, by a screw
conveyor or the like.
In order to prevent a swirling-up of spreading agent as a result of
the compressed air entering the storage container of the dry-bulk
tanker in an area causing swirl-ups such as, in particular, in the
area of the removal of the spreading agent, it is particularly
preferred for the mechanical conveying device to comprise a
conveying chamber. In this arrangement, a conveying device may be
designed, for example, according to an airlock. An opening to the
storage container may thus be opened and closed via corresponding
slide gates, and a connection between the conveying chamber and the
intermediate chamber may be opened and closed via additional slide
gates. Analogous to an airlock, the conveying chamber may thus be
initially filled with binding agent from the storage container by
opening the relevant slide gate, wherein the slide gate is
thereupon closed prior to the slide gate closing the opening to the
intermediate chamber being opened. As a result of this, nothing but
pressure ever enters the conveying chamber from the intermediate
chamber. According to the present invention, the conveying chamber
is thereupon connected to the pressure relief device so that the
pressure in the conveying chamber may be reduced prior to the
airlock being connected to the storage container again, for the
purpose of filling with binding agent, by operating the relevant
slide gate.
In a particularly preferred embodiment, the mechanical conveying
device is a rotary feeder. Said rotary feeder comprises, in
particular, a plurality of conveying chambers arranged about an
axis of rotation. Binding agent enters a conveying chamber open in
the direction of the storage container by way of gravity or by
means of a further conveying device. The respective conveying
chamber is thereupon rotated further by the rotary feeder until the
binding agent in the respective chamber con-tinues from the same
into the intermediate chamber due to gravity. With the aid of a
rotary feeder, it is possible, in particular, to realize a
continuous conveying of binding agent from a plurality of conveying
chambers arranged about an axis of rotation. Compressed air enters
a conveying chamber connected to the intermediate chamber, or the
pressure in said conveying chamber increases, respectively. Prior
to said conveying chamber being connected to the storage container
again, a reduction of pressure in said conveying chamber is
achieved by means of the pressure relief device. To this end, the
connection of the respective conveying chamber to the intermediate
chamber is interrupted during the further rotation of the rotary
feeder. The pressure reduction is effected in this position.
Independent of the type of conveying device used, it is therefore
particularly preferred for the pressure relief device to be
arranged in an area in which a conveying chamber passing through
this area is connected neither to the storage container nor to the
intermediate chamber.
In a preferred development of the pressure relief device, the same
is connected to the storage container by means of a vent line. The
pressure relief device may be formed merely by the connection of
the mechanical conveying device to the storage container via a vent
line. In addition, a valve may be optionally specified in the vent
line. The vent line is preferably connected to an area of the
storage container in which the introduction of air does either not
cause any swirl-ups of binding agent or the same are
non-disturbing. The introduction of the compressed air into the
storage container is preferably effected in an upper area of the
storage container and/or an area of the storage container remote
from the mechanical conveying device.
The storage container preferably comprises a positive pressure
outlet. Said positive pressure outlet preferably comprises a filter
device in order to avoid an escape of binding agent. In a preferred
development, the vent line of the pressure relief device is, in
particular, directly connected to the positive pressure outlet. An
occur-rence of swirl-ups inside the storage container is thereby
avoided.
For conveying the binding agent from the intermediate chamber to
the spreading device, it is preferred for the pneumatic conveying
device to comprise a compressed air source, in particular, a
compressor. The compressor is connected to the intermediate chamber
either directly or via a pressure line. The use of a compressor as
a pneumatic conveying device has the advantage that, on the one
hand, faster conveying of the binding agent from the intermediate
chamber to the spreading device can be realized as a result, and,
on the other hand, such compressor is usually present in dry-bulk
tankers in particular for cleaning purposes.
In a further preferred embodiment, the storage container of the
dry-bulk tanker is connected to a plurality of mechanical conveying
devices. Preferably, a plurality of separate intermediate chambers
are optionally specified, wherein each intermediate chamber is
optionally connected to a separate mechanical conveying device. In
particular, each mechanical conveying device comprises a separate
pressure relief device.
When providing a plurality of intermediate chambers, these are
preferably arranged in series with respect to the pneumatic
conveying process. In a preferred embodiment, the binding agent is
thus conveyed, for example, from a first intermediate chamber into
a second intermediate chamber in a first step, and thereupon from
said second intermediate chamber to the spreading device.
Furthermore, it is also possible to arrange a plurality of
intermediate chambers parallel to one another.
In a preferred development of the present invention, the dry-bulk
tanker furthermore comprises a pneumatic bypass line bypassing the
at least one intermediate chamber. Said bypass line branches off,
on the one hand, in particular, from the pressure line, that is,
the line between the compressed air source and the intermediate
chamber, and is, on the other hand, connected to the conveying
line, that is, the line that leads from the at least one
intermediate chamber to the spreading device. It is thus possible
to generate a higher flow of compressed air or higher pressure,
respectively, in the conveying line, and consequently ensure safe
feeding of a binding agent to the spreading device. When specifying
a plurality of intermediate chambers, the bypass line may
optionally also bridge a single intermediate chamber only.
Furthermore, a plurality of bypass lines is also possible, each of
which bridges a single or a plurality of intermediate chambers.
Branches are also possible in a bypass line bridging a plurality of
intermediate chambers, which is thereupon connected to a line that
connects two neighbouring intermediate chambers. The single bypass
line or plurality of bypass lines may preferably be partially or
wholly discon-nectable or controllable, respectively, so that it is
possible to distribute the amount of compressed air that is
conducted through the at least one intermediate chamber or through
the at least one bypass line, respectively. It is understood that
different bypass lines and/or branches of the bypass lines may each
be provided with sepa-rately controllable valves.
The invention furthermore relates to a conveying system for a
dry-bulk tanker. This is a separate invention which, in a preferred
development, is suitable in particular for the dry-bulk tanker
described above. The conveying system according to the present
invention comprises a mechanical conveying device for conveying
binding agent. Furthermore, the conveying system comprises at least
one intermediate chamber for the reception of the binding agent
conveyed by the conveying device. A pneumatic conveying device is
connected to the intermediate chamber in order to convey the
binding agent to a spreading device. In this design, the spreading
device is not a component part of the conveying system but part of
a separate vehicle or a separate device and, in particular,
component part of a self-propelled ground working machine.
According to the present invention, the conveying system comprises
a pressure relief device which is connected to the mechanical
conveying device. The pressure relief device according to the
present invention features the advantages described above with
reference to the dry-bulk tanker, wherein, in particular, an entry
of compressed air into an area of a storage container of the
dry-bulk tanker is avoided by means of the pressure relief device
when the conveying system is connected to a relevant dry-bulk
tanker.
The individual constructional elements of the conveying system are
advantageously developed as described above with reference to the
dry-bulk tanker. In a particularly preferred embodiment, the
mechanical conveying device is, in particular, designed as a
gravity conveyor. It is furthermore preferred for the mechanical
conveying device to comprise conveying chambers and to be
preferably designed as a rotary feeder. It is additionally
preferred for the pressure relief device to be connected to the
mechanical conveying device in an area in which a conveying chamber
passing through said area is connected neither to the storage
container of the dry-bulk tanker nor to the at least one
intermediate chamber.
As likewise described above in a preferred development with
reference to the dry-bulk tanker, it is preferred for the pneumatic
conveying device to comprise a compressor which is connected to the
at least one intermediate chamber, in particular, via a pressure
line. This may be a compressor already specified on the dry-bulk
tanker. Furthermore, it is likewise preferred for each mechanical
conveying device to be connected to a separate intermediate chamber
provided that a plurality of conveying devices is specified. When
specifying a plurality of intermediate chambers, it is furthermore
preferred for the intermediate chambers to be arranged in series
with respect to the pneumatic conveying device. Furthermore, it is
possible for a pneumatic bypass line bypassing the at least one
intermediate chamber to be specified, which is connected to the
conveying line for feeding the binding agent to the spreading
device.
The invention furthermore relates to a work train for working soils
which are, for example, roads, railway lines, industrial sites, or
the like. The work train comprises an, in particular,
self-propelled ground working machine such as a stabilizer or
recycler. The ground working machine comprises a milling/mixing
rotor inside a rotor housing. Furthermore, the ground working
machine comprises a spreading device for spreading binding agent.
The spreading device is connected to the dry-bulk tanker so that
binding agent can be fed from the dry-bulk tanker to the spreading
device in particular during the operation. In this arrangement, the
dry-bulk tanker is designed as described above and preferably
advantageously developed. The spreading device preferably comprises
a buffer container for binding agent, wherein the buffer container
is thereupon connected to the dry-bulk tanker or the at least one
intermediate chamber, respectively, via the conveying line. The
maximum conveying rate of the binding agent in the conveying line,
which is connected to the buffer container of the ground working
machine, is preferably no less than 400 kg/min and, in particular,
no less than 550 kg/min. The conveying volume is adjustable, in
particular, to the re-quirements or consumption, respectively.
Filling of the buffer container is preferably controlled from the
ground working machine. This may be effected, for example, by means
of appropriate filling level sensors in the buffer container. In
this arrangement, filling of the buffer container may be effected
continuously or intermittently.
BRIEF DESCRIPTION OF THE DRAWINGS
Based on a preferred embodiment, the invention is hereinafter
illustrated in more detail with reference to the enclosed
drawings.
The following is shown:
FIG. 1: a schematic rear view of a dry-bulk tanker,
FIG. 2: a schematic sectional view along line II-II in FIG. 1,
and
FIG. 3 a schematic side view of a ground working machine.
DETAILED DESCRIPTION
The dry-bulk tanker comprises a storage container 10 for binding
agent. The storage container 10 comprises, on an underside 12, two
openings 14 which, in the embodiment presented, are connected, via
a funnel element 16 each, to a mechanical conveying device 18 each,
wherein, in the embodiment presented, the conveying devices 18 are
rotary feeders. The rotary feeders 18 are each connected to an
intermediate chamber 20. The mechanical conveying devices 18 may
also be referred to as mechanical conveyors 18.
From the storage container 10, binding agent enters the funnel
elements 16 through the openings 14. This is effected, in
particular, by means of gravity, wherein a mechanical conveying
device, such as a screw conveyor or the like, may optionally be
additionally specified in the storage container, for example, to
transport the binding agent to the opening 14 from an end of the
storage container 10 remote from the opening 14. The binding agent
slides through the funnel devices 16 into an upper conveying
chamber which is in position 24 (FIG. 2) of the rotary feeder 18.
The rotary feeder 18 rotates about an axis 22 in FIG. 2 in the
direction of arrow 25. Thus, after the chamber in position 24 that
is currently filled with binding agent, the chambers in positions
34 and 32 will be filled with binding agent. From the conveying
chamber in position 30, which is arranged opposite the conveying
chamber in position 24, the binding agent enters the intermediate
chamber 20 due to gravity. The two conveying chambers in positions
32 and 34, following behind the conveying chamber in position 24 as
seen in the direction of rotation 25, are empty. The conveying
chambers in positions 26 and 28 have already been filled with
binding agent and are emptied into the intermediate chamber 20
successively with the continued rotation of the rotary feeder 18 in
the direction of arrow 25.
For pneumatic conveying of the binding agent, compressed air is
introduced into the intermediate chamber 20 by means of a conveying
device which, in the embodiment presented, is a compressor 36.
There is therefore an increased pressure in the intermediate
chambers 20 compared to the environment. Compressed air enters the
first intermediate chamber 20 as seen in conveying direction via
the pressure line 38 connected to the compressor 36. Since the
first intermediate chamber 20 as seen in conveying direction is
connected to the second intermediate chamber 20 as seen in
conveying direction via a connecting line 46, there is increased
pressure also in said second intermediate chamber 20. The relevant
compressed air also enters the conveying chamber of the rotary
feeder 18 that is in position 30. There is therefore an increased
pressure in the chamber in position 32. The pressure in the chamber
in position 34, which is initially also increased, is carried off
via a pressure relief device. In the embodiment presented, the
pressure relief device comprises at least one channel or one line
40 which is connected to an area of the mechanical conveying device
18 in which the emptied conveying chamber, for example, in the area
of position 34, is connected neither to the intermediate chamber 20
nor to the storage container 10. A valve 41, in particular, a
non-return valve, may be optionally specified in the line 40 in
particular in the area in which the line 40 is connected to the
rotary feeder 18. The area of position 34 seen in FIG. 2 may be
referred to as an isolated area.
Since residual amounts of binding agent may still be present in the
chamber in position 34, these may enter the pressure relief device
40, 41. The pressure relief device 40, 41 is therefore connected to
the storage container 10 so that any binding agent present in the
line 40 is conveyed back into the storage container 10. In order to
avoid the formation of positive pressure in the storage container
10, the storage container 10 comprises a positive pressure outlet
44 connected to a filter 42. In order to avoid a swirling of
binding agents in the storage container 10, the line 40 is
connected to the same in an upper area of the storage container
10.
For conveying the binding agent to the spreading device or to a
buffer container 52 (FIG. 3) of the spreading device, respectively,
pressurized air is fed, by means of the compressor 36, to the first
intermediate chamber 20 as seen in conveying direction via the
pressure line 38. The first intermediate chamber 20 is connected to
the second intermediate chamber 20 as seen in the direction of flow
via the connecting line 46 so that binding agent is conveyed from
the first intermediate chamber 20 into the second intermediate
chamber 20 through the connecting line 46. The second intermediate
chamber 20 as seen in the direction of flow is connected to the
spreading device or the buffer container 52 of the spreading
device, respectively, via a conveying line 48.
Furthermore, a bypass line 50 bridging the two intermediate
chambers 20 is connected to the pressure line 38 upstream of the
first intermediate chamber 20 as seen in the direction of flow, and
is connected to the conveying line 48 downstream of the second
intermediate chamber 20 as seen in the direction of flow. The
bypass line 50 is connected to the connecting line 46 via a
branching line 51. For control of the distribution of the
compressed air, an in particular controllable valve may be
arranged, for example, in the bypass line 50 and/or in the
branching line.
Depending on the design, the pneumatic conveying device therefore
comprises a compressed air source which, in the embodiment
presented, is a compressor 36, and lines. In addition to the
compressed air line 38, the pneumatic conveying device may comprise
the lines 46, 50, 51 and 48. The pneumatic conveying device may
also be referred to as a pneumatic conveyor.
For conveying the binding agent, pressure is applied to the
pneumatic conveying device from a pressure source which, in the
embodiment, is the compressor 36. This leads to increased pressure
in the conveying device compared to the environment. For
transferring the binding agent from the conveying chambers into the
intermediate container 20, the conveying chambers are connected, in
an air-permeable fashion, to the intermediate container 20 and thus
to the pneumatic conveying device exhibiting a positive pressure
compared to the environment. In the embodiment presented, there is
therefore an increased air pressure compared to the environment
also in the conveying chambers in positions 30 and 32. In the
conveying chamber in position 30, there is an increased air
pressure due to the currently present air-permeable connection to
the pneumatic conveying device. In the conveying chamber in
position 32, the pressure was increased when the same was connected
to the intermediate chamber 20 in an air-permeable fashion for the
discharge of binding agent. With the continued rotation of the
rotary airlock 18, said air-permeable connection was interrupted;
the pressure present can, however, not be reduced. According to the
present invention, the pressure relief device 40, 41 is specified
in position 34 of the mechanical conveying device 18.
The dry-bulk tanker 54 presented in FIG. 2 is connected to the
ground working machine 56 presented in FIG. 3 via the conveying
line 48. The ground working machine 56 comprises the buffer
container 52 which is connected to the conveying line 48 and is
used for the intermediate buffering of binding agent. A spreading
device 58 not presented in further detail is connected to the
buffer container 52. Binding agent is spread on a surface 60 of a
ground to be milled-off, such as a road surface, via the spreading
device 58. The surface 60 is thereupon removed by means of a
milling and mixing rotor 62. Such ground working machine with
buffer container 52 is described, for example, in DE 10 2009 008
884.
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